Redwing

[grubscrewParticipant @grubscrew]

Hi Chaps

When it comes to constructing model kits such as the Wyvern, Redwing etc, do most builders stick to the plans and use the recommended BA, UNF etc threads or do you convert to metric for ease, availability and so forth?

Cheers, Grubscrew

[JasonBModerator @jasonb]

In the past with the American designs I have maintained the imperial dimensions and stock sizes but changed the UNC to BA and pipe threads to BSP. More recently I have fully converted engines such as the RLE to metric (not just a mathmatical conversion) so the materials are metric and used metric threads which obviously can be cut straight onto the ends of the metric stock.

The half way house is a mix and match which may just entail changing to metric fixings which I have done a few times or a step further you may use metric round stock but still make the parts to the imperial length.

Really depends on what you are happy working with and what material and fixings are readily available.

[Roderick JenkinsParticipant @roderickjenkins93242]

I generally use metric fastenings where I can.  I never use any US threads because I don’t have any US taps and dies.  My Hoglet and Farm Boy are mostly ISO metric coarse with some BA where that seems more appropriate and some ME threads where fine threads are required.

Rod

[Bo’sunParticipant @bosun58570]

Just remember, if you’ve used a mix of thread types, make a note for later down the line.  Ask me how I know?

[DiogenesParticipant @diogenes]

I generally use metric too – the smaller sizes seem to cheapest in quantity so I always have ‘stock’ to use; also ‘nuts & bolts’ with ‘one-size-smaller’ heads have (still?) to come from the EU so it saves P&P. – stamped, ‘stock’ sized small metric fittings don’t (IMO) suit every engine, if you want a ‘scale’ look.

BA also come in more ‘scale’ looking sizes and are perhaps more readily available in the UK.

Use what looks ‘right’ to you eye, and falls easily to hand – I think it probably it pays to ‘standardise’ at some point.

 

[grubscrewParticipant @grubscrew]

Thanks for the advice guys.

I do love the look of the ‘self coloured’ BA threaded fasteners on models, but BA only go ‘so’ large.

My OCD won’t allow me to mix thread types, so I think I will go down the metric route from now on.

Does anyone know of a suitable supplier of model engineering sized, ‘self coloured’ metric fasteners?

[JasonBModerator @jasonb]

I get mine from GHW in Germany, you want the “model nuts “and “model Screws” these have a smaller hex than ISO standard so look a lot better as well as being taller and fully machined not stamped out and rounded. There is also Knupfer. who do similar.

Polly sort of do them but the last time I spoke with teh new owners they did not have much in stock.

You are unlikely to need much over M4 on most of these engines, maybe the odd M5 or M6 in which case I Just mill my own hex heads or nuts from round stock.

You will still probably have to mix a few thread types if your engine uses a 1/4″ x 32 sparkplug or you want to plumb water and exhaust with off teh shelf elbows you will need BSP. Metric Fine for the stuff that needs a fine thread that would have been ME or American Model Thread

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